Answer:
18 DAYS IS THE HALF LIFE OF THE RADIOISOTOPE.
Step-by-step explanation:
Using the formula
Nt = No * (1/2)^t/t1/2
where;
Nt = amount remaining = 25 g
No = Initial amounrt of the radioisotope = 50 g
t = time elapsed = 18 days
t1/2 = half life = unknown
Substitute the values into the equation and obtain the half life of the radioisotope;
Nt = No * (1/2) ^t/t1/2
25 = 50 * (1/2) ^18/t1/2
25 /50 = (1/2)^18/ t1/2
1/2 = (1/2)^18/t1/2
1/2)^1 = (1/2)^18/t1/2
1 = 18/t1/2
t1/2 = 18 days.
So therefore the half life of the radioisotope is 18 days.